Although restaurants in downtown Iowa City come and go, The Brown Bottle Restaurant is celebrating 40 years of lasagna in September.

The Brown Bottle Restaurant franchise is a family chain started by Iowa City location owner Dave Landau’s parents, Don and Donna, beginning on College Hill in Cedar Falls in 1972.

The Iowa City location opened in 1974 in the MidWestOne bank building.

Landau’s parents opened The Other Place pizza joint in 1967 and Landau said it was “hugely successful” among the college crowd.

Dave said the restaurant sold so much pizza and Schlitz beer that the Milwaukee brewery invited them to the headquarters to sample their new invention of the brown bottle, which protected the beer from light, extending the shelf life.

The Brown Bottle carved a niche for itself by serving each dish in its own individual crock, which the Landaus said has been the key to their success.

Dave’s wife, Gina, said the restaurant sold nearly 7,200 pieces of its lasagna last year.

“You can kind of use a spoon, scoop out half of it, and as you are finishing the first half, the second half is still piping hot,” she said.

Dave and Gina have owned the Iowa City location since 1998, opening a North Liberty restaurant in 1994. Dave said his brothers own three other Brown Bottle locations.

Gina said the key to the restaurant’s success is consistency, hot food and affordability.

“If you ordered a lasagna in 1974, it should be exactly the same today,” she said.

Dave and Gina said although they spend their days and nights together, it balances well as they manage the front and back of the house without “stepping on each others toes.”

“There’s a lot of people who ask us how we can be together all the time, because we virtually are,” Dave said. “All the time.”

Nancy Bird, executive director of the Iowa City Downtown District, said downtown is a “very competitive restaurant market” and the Brown Bottle’s longevity proves it has “won over the community after all these years.”

“To be in business for 40 years and weather the ups and downs of the economic cycle is no small feat,” she said. “It speaks to Brown Bottle’s high standards for quality food and service.”

Gina said the restaurant will honor a 20 percent discount on diners’ bills Tuesday and Wednesday. The owners also will draw names to give away four $50 gift cards.